Dishwashing machine



1934- I s. STODDARD ET AL 1,971,543 I DISHWASHING MACHINE Filed April 24, 1930 2 Sheets-Sheet 1 lnderwrzs. Ed ar 5- Sfoddard.

wil cud. Cliykert 1934. s. STODDARD El AL 1,971,543

DISHWASHING MACHINE Filed April 24, 1950 2 Sheets-Sheet 2 Ed ar 5 fiioddard wt ,ard C-R ykerf- Patented Apgl 28, 1934 i t l p UNITED STATES PATIENT OFFICE nrsnwasnme Edgar s. Stoddard, Berwyn, and. Willard o.-

-Rykert, Hinsdale, Ill., assignors to like; Conover Company, Chicago, 111., a corporation of Illinois Application April 24, 1930, Serial No. 446,809

4 Claims. (01. 299-53 The present invention relates to. impellers for In thefta'nk 11 are positioned the dish racks 31 agitating, spraying and moving liquids, and it of any Suitable construction. These racks are particularly relates to impellers for use in the intended to support dishes or similar objects spray-projection type of dishwashing machines. in the washing chamber substantially above the In these spray-projection machines, more fully impeller and above the pool level. The dishes or described in copending application Serial No. other similar obje'ctsare so supported by means.

, 389,696 filed August 31, 1929, now Letters Patent of the rack 31 that the liquid spray-projected by No. 1,937,100 issued November 28, 1933, it is dethe impelleriwill contact with them at such an sirable to utilize a small amount of cleansing angle as to'cleanse them most effectually. The liquid and to throw the cleansing liquid tangennormal static water level is. approximately intially upwardly and outwardly from a. low level dicated at 32. It will be noted that the normal toward, and upon, dishes and similar objects at static water level is regulated so that the ima high velocity. The dishes at all times are subpeller 34, is only partially immersed. h dystantially above the level of the pool of cleansing namic water level usually will be materially liquid in the bottom of the machine and the; lower than the static water level because a subcleansing action is exclusively due to the action stantial amount of liquidwill be in the course of a projected or reflected spray. It is desirable of beingspray-projected into the washing chamto project the liquid spray at such velocity that her and will also be retained upon the rack strucit will have a force sufficient to remove the adture or the objects being cleansed. i herent dirt from the surfaces vof the dishes and The water-propelling or circulating device 34 other objects. is positioned in the lower central part of the tank An object of this invention is to provide an imand is so designed as to elevate small sheets or proved impeller for spraying liquids which is streams of water from the pool in the lower porparticularly adapted to be utilized in a spraytionof the vessel at, or closely adjacent, the cen 5 projection type of washing machine. tral axis of the machine, through acomparatively Another object of this invention is to provide small compass to'a point slightly above the pool an impeller which may be centrally positioned level; Such elevated streams of water are thrown and which will cooperate with a centrally'loupwardly and outwardly from such elevated point cated drain-level device. I at a high rotational velocity in intermittent or A further object of the present invention is to continuous streams and/or sheets. 35 provide in'combination with a spray-projection T e impeller, Shown in g- 1 and more fully dishwashing machine impeller, suitable apparatus in Figs. 2 to 4 comprises a head 35' which is for directing the flow of the liquid being supplied attached to the top of the motor shaft and two to the impeller and also the course of the liquid vat g d p jectin b ades 36 and 37. The

being projected by said impeller, head 35 (see Figs. 2', 3 and 4) has a central coni- Other objects will appear during the course of cal portion 20 and is provided with outwardly the following description. projecting fins 21 which support the upper ends The following drawings represent several em- 0f the blades 36 d These fins are 50 p bodiments of the invention, to which the lnvenportioned and positioned that" the line 0f J' e tion, however, is by no means restricted: .30 between the blades 36 and 37 and the fins 21 Fig. 1 represents a vertical sectional view-of a will op nwardly and downwardly until they dishwashing machine with the impeller in poreach the bottom of the conical portion 20. The sition; v line 30 should reach the bottom at a point 01' Figs. 2,. 3 and 4 represent enlarged side and the nical portion 20 in advance of a point top views of the embodiment of the impeller d ly under the upper Outer p t 23 of the shown in Fig. 1; and fin 21 in the direction of rotation.

Fig. 5 showsthe driving connections of the e head piece 5 P ma i y serves as a supimpeller and the cooperating centrifugal in secp l i g ember designed to attach the rotating tion illustrating their positions and attachments. blades to the p of the d v g or motor shaft.

In Fig. 1 the tank of the dishwashing machine t may be made cylindrical or of other shape 11 i provided with a removable cov r 12, Th than "that shown. -It is desirable to attach the impeller 34 is disposed centrally in the lower blades to the head piece in such manner that the portion of the tank 11 and is actuated by means Surface of the blade Will blend into the ead piece. of a vertical shaft which extends through the In the p s t em od ead piece 35 is so bottom of the tank (see Fig. 5). d signed as t ive ma um strength to the 1m blade attachment and result in minimum interference with the spray projection. The upper surfaces of the fins 21 constitute a continuation of the elevator and projector surfaces and assist in the spray-projection action adjacent the line 30.

The circular inclined or screw surfaces 38 and 39 forming the lower elevating portions. of the blades 36 and 37 extend down to a point below the. normal surface 32 of the liquid pool contained in the bottom ofthe washing chamber of the tank 11. The elevator surfaces 38 and 39 terminate in the curved edge 24. I

In the present embodiment, both blades 36 and 37 are of the same size and shape. As shown (see especially Fig. 4) the inclined surfaces 38 and 39 at the bottom of the blades 36 and 37 terminate within a range about 180 to 270 of the commencement of the deflector on the head 35.

In the embodiment shown they preferably extend around the head 35 an angular distance between about 205? and 235. i

The upper portions of the blades at their line of attachment30 to'the head 35 approach the vertical as indicated at 40 (see Fig. 3). The upper substantially vertical surface 40 turns away from the head piece 35 in the direction of rotation. The highest point 23 of the deflector is so positioned that it will be substantially at the top of theline of jointure 30.

The projector and elevator surfaces are so shaped that the traces of vertical radial intersecting planes will be approximately parabolas. The curvature of the parabolas will increase as the top of the cylinder is reached starting with a substantially very-slight curvature at the bottom of the blade. The water in ascending the elevator and projector surfaces will not rotate at the same speed as the surfaces themselves, due to its slip. The rotational speed of the liquid body on the impeller blade,' however, will increase as the top of the blade is approached, starting from almost zero at the bottom of the blade and increasing tqa maximum at the top. The radial trace above described at any place on the surface of the blade should be approximately a parabola of the same shape and value as the parabola which would be formed by the liquid, if rotating in a vessel at the same rotational velocity. The resulting shape of blade will be a modified parabolic surface which at any place will have substantially the same shape and value as the parabolic surface which would be taken by the water upon it, if rotating at the same rotational velocity. This parabolic surface may be modified to produce the necessary directional flow and/ortdistribution of the cleansing fluids.

Starting from the terminating upper edge of the inclined surface, the radial width of the inclined surfaceincr'eases so that at the point of about 90 to"l, approximately 135 in the embodiment shown, horizontally in advance of the vertical terminating plane 40 in the embodiment of the invention shown, the impeller will achieve its maximum width as indicated at 44. From place 'of maximum width 44, the width of the inclined surface very rapidly decreases until it terminates at the point 45. The amount of this decrease will be governed by the shape, size and pitch of the bottom of the tank and the amount of cleansing fluid used. The inclined surface is so widened and curved that the'efflcient projection of the spray will not be interfere with by the centrifugal force tending to' throw the water off the blade sidewardly. t

' Both the concavity and the pitch of the elevating and deflecting surfaces mayincrease 'as the top of the impeller is approached-as in the embodiment shown. The present pitch varies from about 15 to the horizontal at the bottom to This spacing may be uniform from the place of .attachment of the blade to its termination.

This proportion may vary so that the distance from the edge 46' to the axis 48 will be between one-fourth and three-fourths of the width of the blade at the place 44. The radial width of the blade at its point of commencement, that is, from the point 22 .to the outer edge of the blade, will be about one-half of the radial width of the blade at thepoint 44. Of course the actual width, ofthe blade will be controlled not only by the radial width but also by the pitch thereof. The maximum radial distance of the outer edge of the blade at the point 44 may preferably be somewhat less than the height of the impeller from the highest point 23 to the lowest point 45, and in the embodiment shown "this distance is between and K; of the height of the impelling device. It has been found satisfactory to vary this height so that it will be between one to two times the maximum radial width 44. It therefore follows that the impeller while rotating will sweep out anelliptical volume which in the embodiment shown will'be of greater horizontal dimension than vertical dimension. 3

' The impeller in the present embodiment is so will be four to ten or more times the maximum radial distance 44. In the embodiment .shown, 'the tank diameter is approximately seven times ,the distance from the axis 48 to the outer edge of the blade at the point 44. The impelling device will project upwardly into the washing chamber above the dynamic level of the cleansing fluid a distance which is approximately proportioned to'the tank that the tank diameter to of its total height. It preferably should I not extend into the well 60; The impeller 34 is adapted to cooperate with the draining bottom,

which, it is noted, is formed of a series of frustrumed conical portions of increasing inclination to the horizontal. The outer portion of the draining bottom 61 is joined by an intermediate portion 62 of increasing slope. which in turn isflnally joined by means of the substantially vertical portion 63. The bottom is flnally terminated by the slightly sloping portion 64 which is approximately parallel to the outer portion 61. The conical portions 63 and 64 may be considered to forma well 60 above which the impeller is posi tioned. v

Positioned in the well and over the impeller is an impeller guard device '70 which is fitted into position by means of the circular groove 71 which cooperates with the lower ends 72 of the guard. Attached to the side of the guard are a series of plates 73. These plates 73 serve to direct the water which descends to the impeller over the draining bottom, and they also tend to decrease the amount of whirl in such water as it descends. Attached to the top of the guard '70 are short vertical baflle plates 77 which direct the water and other articles placed in the central upper rack structure. I

The impeller is driven by a motor shaft 81, which extends upwardly into the well of the tank. At the top of the shaft is a shouldered threaded portion 82 which is screwed into the middle of the conical head 35. This shaft 81 is provided with the bearing 83 which his into the bottom of a bearing sleeve 85 attached to the top of the motor casing. Surrounding. the bearing sleeve 85 is the rotating impeller sleeve 86 which end of this rotating sleeve '85 is attached a cen'- trifugal pump 97 which rotates in the lower well chamber 98' and serves 'to remove waste liquids from the washing chamber into the drain-line 99 (see Fig. 1).

The wings of the impeller are adapted to embrace and extend around a drain-level connection shown in side view in Fig. 1 and in side section in Fig. 5. This drain-level connection is more fully shown and described in a copending application Serial No. 449,186, flied May 2, 1930. Referring to Fig. 5, covering the lower well chamber 98 is the well cover 76 which is centrally provided with an opening to receive the drive shaft 81. Around the periphery of this opening is a rotary valve 92' spaced from the sleeve 86 and adapted to be operated by the link rod 104. Openings 93 are provided through the rotary valve. An overflow tube 94 is mounted around the shaft 81 'and sleeve'86 and seated on the inner rotary member of the valve 92 forming a watertight seal therewith. The height of this 86, thus forming a liquid communication from' the tank 11' to the well chamber 98 by means of the passageway formed between the overflow tube .94 and the impeller sleeve-86.

It is evident that by turning the rod 104 the I openings 93 in the valve 92 may be made to oooperate with one another to] permit water in the tank 11 to pass directly by gravity from tank 11 through the openings 93 to the well chamber 98. When the rod 104 is oppositely turned, openings 93 are rotated out of alignment and this avenue of escape for the water in tank 11 is closed. While this avenue is closed, the only other means of escape is by way of the overflowv tube 94, and this means, will be operative only when the water level in tank 11 reaches a height equal to theheight of the top ofthe tube.

The impeller blades 36 and 3'! extend down and and'around the overflow tube and, while in opmit easy access of the water to the overflow tube,

but it is adapted to iit sufllcientlyclose to *the' overflow tube and'the tank bottom that a substantially quiescent body of water is maintained within and beneath the shell- I The operation of the impelling device is as follows: The impeller device will be rapidly rotated by the shaft 81 at a rotational speed of about 1000 to 2500 R. P. M. The lower curved edges 24 will cut into the pool of cleansing and rinsing liquid and will elevate portions of it to the upper more vertical portions of the blades 36 and 37 and spray-project it outwardly and upwardly into the washing chamber. Some of the liquid thus spray-projected will contact with the small baiiies I7 and will be reflected more directly into the central upper rack. The returning liquid will flow downwardly and inwardly over the draining bottom'6linto the well and it will be directed into the well by means of the baflies 74. These baflles will serve to decrease any rotational movement it may have.

When the rinsing or cleansing operation is finished, the valve 93 may be turned so as to drain the waste liquids from the well 60 and the washing chamber into the centrifugal chamber 98, from whence they will be exhausted by means of the centrifugal device 97. I

This application is a continuation in part of applications Serial Nos. 266,496, filed April. 2, 1928, 290,344, tlled July 5, 1928 and 344,111, filed March 5, 1929 now Letters Patent No. 1,870,317 issued August 9, 1932.

The foregoing detailed description has been given for cleamess of understanding only and no unnecessary limitation should be understood therefrom, but the appended claims should be construed as broadly as permissible in view of the prior art. 1

What is claimed is:

l. A liquid agitating and impelling device com- A prising a central conical member, a plurality of fins extending outwardly from said conical member. and outwardly then downwardly extending blades attached to the edges of said flns.

2. A liquid agitating and propelling device comprising a central conical member provided with outwardly extending fins which join at their lower extremities with the conical member and extend upwardlyand outwardly a substantial distance from the conical member, and an equal number of outwardly then downwardly extending. blades of decreasing pitch attached at their upper ends to the edges of said fins.

3. A spray projecting device comprising a central headmember tapped to receive an upwardly extending drive shaft, a pair of fins extending outwardly and upwardly from'diametrically opposite sides of said member, which flns' adjacent the top of the head member decrease in thickness outwardly until they form an edge, and a pair of elevating and projecting blades the upper ends of which are attached to the edges of the fins of said head member and which first extend outwardly'and then .downwardly around the axis of said conical member.

4. A spray-projecting impeller, comprising a head member, and outwardly and downwardly extending blades attached thereto, the inner edges of said .blades being removed a substantial distance from and extending downwardly around said head member, and said blades having a width I which first increases and then decreases, a max- I imum radial width being reached at about to 180 from the place of attachment of said blades to the head member.

I EDGAR. S. STODDARD. WILLARD C. RYKERT. 

